Excessive extracellular matrix metalloproteinases (MMPs) activities in the cornea can lead to cornea ulceration. Cicatrization due to cornea ulceration is a major cause of blindness and impaired vision. We are concerned about the effect of commonly used eye medications and UV radiation on corneal MMPs. We propose to study the four major corneal MMPs: gelatinase A, gelatinase B, collagenase and stromelysin under normal, injured and diseased conditions in organ culture. Pig corneas will be used. The effect of eye medications and UV radiation on the net synthesis of each of these MMPs will be evaluated. The medications to be tested include agents for antibacterial, antifungus, antihistamine, pupil dilator, antiglucoma, anticholinergic and anti-inflammatory. The effect of these medications of the activity of each purified MMPs will also be studied. The results of our work may lead to a better understanding of these medications and UV radiation on the structural integrity of the cornea. Our long term goal is to determine the effect of environmental agents on the structural integrity of the cornea.